Organic and Mineral Fertilizers Compared by Yield, Quality, and Composition of Spinach1

Abstract

Abstract Mineral fertilizers increased yield and concn of N in leaf tissue more than organic fertilizers when nutrients were applied to make mineral and organic rates identical. All 3 types of fertilizer treatments increased N concn in plant tissues over the control plots. Organic fertilizer resulted in significantly higher P concn in plant tissue than did MF or MFSN for every crop. Mineral fertilizer increased Ca uptake the 1st and 3rd crops, but significantly reversed those results in the 2nd (overwintered) crop. Organic fertilizers increased Fe uptake significantly over MF the 2nd and 3rd crops and significantly increased Na uptake more than either MF or MFSN every crop. Of the 13 variables studied, concn of 10 variables was greater in the overwintered crop than in the spring planted crops.